Biomedical subjects
A M Hutter
Publications and source records attributed to A M Hutter.
Striving for effective communication.
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Viral myocarditis mimicking acute myocardial infarction.
Anecdotal reports have shown that myocarditis can mimic acute myocardial infarction with chest pain, electrocardiographic (ECG) abnormalities, serum creatine kinase elevation and hemodynamic instability. Thirty-four patients with clinical signs and symptoms consistent with acute myocardial infarction underwent right ventricular endomyocardial biopsy during a 6.5-year period after angiographic identification of normal coronary anatomy. Myocarditis was found on histologic study in 11 of these 34 patients. Cardiogenic shock requiring intraaortic balloon support developed within 6 h of admission in three (27%) of the patients with myocarditis. The mean age of the group with myocarditis was 42 +/- 5 years. A preceding viral illness had been present in six patients (54%). The ECG abnormalities were varied and included ST segment elevation (n = 6), T wave inversions (n = 3), ST segment depression (n = 2) and pathologic Q waves (n = 2). The ECG abnormalities were typically seen in the anterior precordial leads but were diffusely evident in three patients. Left ventricular function was normal in six patients and globally decreased in the remaining five patients, whose ejection fraction ranged from 14% to 45%. Lymphocytic myocarditis was diagnosed in 10 patients, and giant cell myocarditis was detected in the remaining patient. Four patients with impaired left ventricular function received immunosuppressive therapy with prednisone and either azathioprine (n = 2) or cyclosporine (n = 2). All six patients whose left ventricular function was normal on admission remain alive in functional class I. Of the five patients with impaired systolic function, ejection fraction normalized in three of the four patients who received immunosuppressive therapy within 3 months of treatment and in the one patient who received only supportive therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
The ACC and health care policy: a time for unity and action.
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23rd Bethesda conference: access to cardiovascular care. Task Force 4: Influence of private sector parties on access to cardiovascular care.
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Prognostic utility of predischarge dipyridamole-thallium imaging compared to predischarge submaximal exercise electrocardiography and maximal exercise thallium imaging after uncomplicated acute myocardial infarction.
The prognostic value of predischarge dipyridamole-thallium scanning after uncomplicated myocardial infarction was determined by comparison with submaximal exercise electrocardiography and 6-week maximal exercise thallium imaging and by correlation with clinical events. Two endpoints were defined: cardiac events and severe ischemic potential. Of the 40 patients studied, 8 had cardiac events within 6 months (1 died, 3 had myocardial infarction and 4 had unstable angina requiring hospitalization). The finding of any redistribution on dipyridamole-thallium scanning was common (77%) in these patients and had poor specificity (29%). Redistribution outside of the infarct zone, however, had equivalent sensitivity (63%) and better specificity (75%) for events (p less than 0.05). Both predischarge dipyridamole-thallium and submaximal exercise electrocardiography identified 5 of the 8 events (p = 0.04 and 0.07, respectively). The negative predictive accuracy for events for both dipyridamole-thallium and submaximal exercise electrocardiography was 88%. In addition to the 8 patients with events, 16 other patients had severe ischemic potential (6 had coronary bypass surgery, 1 had inoperable 3-vessel disease and 9 had markedly abnormal 6-week maximal exercise tests). Predischarge dipyridamole-thallium and submaximal exercise testing also identified 8 and 7 of these 16 patients with severe ischemic potential, respectively. Six of the 8 cardiac events occurred before 6-week follow-up. A maximal exercise thallium test at 6 weeks identified 1 of the 2 additional events within 6 months correctly. Thallium redistribution after dipyridamole in coronary territories outside the infarct zone is a sensitive and specific predictor of subsequent cardiac events and identifies patients with severe ischemic potential.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary angioplasty in acute myocardial infarction: should it be done? To whom? When?
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Guidelines for ambulatory electrocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Subcommittee on Ambulatory Electrocardiography).
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Continuous monitoring of left ventricular function by an ambulatory radionuclide detector in patients with coronary artery disease.
Global left ventricular function and a modified V5 electrocardiographic (ECG) lead were continuously monitored by a radionuclide recorder in 12 normal subjects and 39 patients with coronary artery disease while the subjects were performing various daily activities. The ambulatory studies revealed that walking on a level surface caused 11 of 12 normal subjects and 18 of 32 patients to increase their left ventricular ejection fraction by greater than 6% units. A transient decrease in left ventricular ejection fraction (6 to 18%) lasting greater than or equal to 1 min was observed on 36 occasions in 16 patients with coronary artery disease; 12 episodes were accompanied by chest pain or shortness of breath and 24 were asymptomatic. Electrocardiographic ST segment depression suggestive of ischemia was recorded in 6 of the 12 symptomatic and 5 of the 24 asymptomatic episodes. In 10 of the 12 symptomatic episodes, left ventricular ejection fraction began to decrease 30 to 90 s before the onset of symptoms. These studies suggest that continuous monitoring of both left ventricular function and the ECG may permit stratification of episodes of ST depression suggesting ischemia by the degree of left ventricular dysfunction they produce.
Cardiovascular disease in the elderly. Valvular and congenital heart disease.
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Underestimation of prosthetic mitral valve areas: role of transseptal catheterization in avoiding unnecessary repeat mitral valve surgery.
In patients with symptoms of heart failure after mitral valve replacement, identification of a stenosed prosthesis may be difficult. Twelve such patients were evaluated, presenting at a mean of 8.4 years after mitral valve replacement (four mechanical, eight porcine). Transvalvular pressure gradients were obtained using both indirect (pulmonary capillary wedge) and direct (transseptal catheterization) measurements of left atrial pressure. In all 12 patients, the diastolic gradient across the prosthetic valve was overestimated when pulmonary wedge rather than transseptal measurements were used. Calculated mitral valve prosthetic area was underestimated by the pulmonary wedge determinations. These findings may be caused by either the phase delay of the pulmonary wedge V wave relative to the transseptal V wave, resulting in a higher diastolic mean left atrial pressure, or the faulty wedge determinations in the setting of pulmonary hypertension, or both. In patients being considered for repeat mitral valve replacement because of prosthetic valve stenosis, transseptal catheterization allows for more accurate determination of prosthetic valve area and more accurately defines the need for repeat mitral valve surgery.
Predicting results of coronary angiography.
This study compares the ability of various risk factor combinations to predict the extent of coronary artery disease found on coronary angiography. Risk factors were measured in 99 patients prior to coronary angiography. Clinical, epidemiological, psychosomatic, and combined orientations were compared as to their ability to predict angiography results. The clinical orientation was the most successful in predicting vessel disease (p less than .0001), followed by the epidemiological model, which was also successful (p less than .03). In contrast, psychosomatic factors were not accurate predictors of vessel disease. By combining all of the orientations, the accuracy of prediction is improved.
The incidence and pattern of angina prior to acute myocardial infarction: a study of 577 cases.
In order to determine the incidence and pattern of angina as a premonitory symptom of acute myocardial infarction, 577 consecutive patients with acute myocardial infarction were questioned shortly after hospital admission about the presence and pattern of chest pain prior to onset of infarction, with particular emphasis on the month prior to infarction. Two hundred and seventy-six patients (48 per cent) had no angina before infarction (Group I), whereas 301 (52 per cent) did. One hundred and seventy-nine patients (31 per cent) had a history of chronic angina, and of these, 75 had no change in the pattern of angina prior to infarction (Group II) while 104 noticed worsening of their symptoms in the month prior to infarction (Group III). One hundred and twenty-two patients (21 per cent) had new onset angina in the month prior to infarction (Group IV). The number of patients with unstable angina prior to infarction (Groups III and IV) was therefore 226 or 39 per cent of the total series. In patients with unstable angina, the increase in severity of symptoms or the development of new onset angina occurred within a period of 1 week or less in 69 per cent. Patients with a history of previous infarction or chronic angina had a higher incidence of unstable angina prior to infarction than patients without such a history (p less than 0.05). Patients with prior angina (Groups II, III, and IV) had a higher incidence of subendocardial infarction than patients without angina (p less than 0.05). The hospital mortality rate in the four groups did not differ significantly.
Right ventricular infarction. Clinical diagnosis and differentiation from cardiac tamponade and pericardial constriction.
Twelve patients with a clinical diagnosis of right ventricular infarction are described. All had acute inferior wall myocardial infarction associated with the bedside findings of jugular venous distension, clear lungs on auscultation, and arterial hypotension. Hemodynamically, there was elevation of right-sided filling pressures not explained by normal or minimally elevated pulmonary wedge pressures. Four patients had an incorrect diagnosis of acute cardiac tamponade. However, a review of the data showed that the hemodynamic features of right ventricular infarction more closely resemble those of pericardial constriction, a point that may be helpful in distinguishing right ventricular infarction from cardiac tamponade. Invasive and noninvasive techniques that exclude the presence of pericardial fluid and suggest enlargement and abnormal contractility of the right ventricle were helpful in establishing the diagnosis of right ventricular infarction in several patients.
Type A behavior and angiographic findings.
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Intraoperative cardiac arrhythmias.
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Patterns of haemodynamic alteration during left ventricular ischaemia in man. Relation to angiographic extent of coronary artery disease.
Haemodynamic changes produced by rapid atrial pacing (60 patients, 52 of whom developed angina) or in association with spontaneous angina (32 patients) were measured in 92 patients with angiographic coronary artery disease. The extent of coronary artery disease was scored by the jeopardy score system (range 0 to 12). The haemodynamic changes induced by ischaemia occurred in 3 patterns: pattern I, no change in filling pressure or in mean systemic arterial pressure; pattern II, a rise in filling pressure and a rise in mean systemic arterial pressure; pattern III, a rise in filling pressure, but no significant change or a fall in mean systemic arterial pressure. In patients who had a pattern II or a pattern III response to ischaemia, the change in mean systemic arterial pressure was linearly related to the corresponding change in cardiac output. The likelihood of a patient showing a given pattern of ischaemia-induced haemodynamic change was related to the extent of coronary artery disease; of 22 patients with jeopardy scores of 2 or 4, 91% exhibited pattern I, 9% pattern II, and none pattern III; of 39 patients with jeopardy scores of 6 or 8, 40% exhibited pattern I, 22% pattern II, and 38% pattern III; of 31 patients with jeopardy scores of 10 or 12, 12% exhibited pattern I, 10% pattern II, and 78% pattern III (P less than 0.01). Among the 54 patients in whom serial cardiac output determinations were available, a decline of the left ventricular function curve during ischaemia was demonstrable in 8% of those with a pattern I response, in 54% of those with a pattern II response, and in 90% of those with a pattern III response (P less than 0.01). The pattern of response was unrelated to resting angiographic left ventricular ejection fraction, whether ST segments became elevated or depressed, or whether ischaemia was pacing-induced or spontaneous. These results suggest that the haemodynamic response to ischaemia is determined by the fraction of the left ventricle that becomes dysfunctional during ischaemia.
Primary pulmonary hypertension treated with oral phentolamine.
A patient with symptomatic primary pulmonary artery hypertension underwent therapeutic trials with parenteral and oral phentolamine. Before drug therapy, he manifested marked increases in pulmonary artery pressure and pulmonary arteriolar resistance during exercise. This hypertensive response to exercise was significantly attenuated by parenteral phentolamine. He also manifested sustained hemodynamic improvement with the same degree of attenuation of exercise-induced increases in pulmonary artery pressure and pulmonary arteriolar resistance 7 months after initiation of therapy with oral phentolamine. Twenty months after initiation of therapy, the patient continues to enjoy symptomatic improvement with a marked increase in exercise tolerance.